Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. HMS Swordfish was an experimental submarine built for the Royal Navy in the hope of achieving a speed of 20 knots (37 km/h) by using the steam turbine rejected from a previous attempt, HMS Nautilus. This submarine was developed by Scotts Shipbuilding and Engineering Company, Greenock, from a design prepared for the Royal Navy by the Italian submarine designer Cesare Laurenti (1865-1921), whose designs were at that time in use by several European navies.